1. On your iPad, open the Settings app
2. Navigate to the "iTunes and App Store" section on the left.
3. Tap on your AppleID name
4. A popup window will appear - select "View AppleID"
5. On the next screen tap "Payment Information"
6. Finally, on the Account Payment screen, you may see a message "You must verify your payment info before you can make purchases".
7. Check all of your payment details here. Often all you need to do is enter the 3 digit security code form your credit card.